Since December 2014, a measles outbreak that began at Disneyland in California has grown to more than 100 cases in multiple states. Most of the people who have gotten sick were not vaccinated against measles. This is a stark reminder of the importance of making sure your children are fully vaccinated.

The following are answers to questions many parents have about this measles outbreak.

I thought measles was a mild illness, why the alarm now?

Measles was once a common childhood disease and almost an expected part of growing up. While most children recovered from the measles without problems, many others did not. In some children, the infection caused pneumonia and in a few, encephalitis (infection of the brain) and even death. Of every 1,000 people who got measles, 1 to 2 would die. Before the measles vaccine was available, every year an average of 450 people died from measles; most of them were healthy children.

Thanks to the success of the measles vaccine, we are now able to protect children from the measles. However, in recent years some parents have refused or delayed vaccinating their children out of fear or misinformation about the safety of the measles vaccine. This means there are more unvaccinated children, adolescents, and adults in our communities. Choosing to not vaccinate your children not only leaves them susceptible to measles, but also exposes other children to measles. This includes infants who are too young to be vaccinated and those who are unable to be vaccinated due to other health conditions. In addition, measles is still common and large outbreaks still occur in many other parts of the world. Thus, measles is just a plane ride away, or even closer.

How is measles spread?

The measles virus spreads easily through the air when an infected person sneezes or coughs and someone nearby inhales the infected droplets. It can also be transmitted by direct contact with fluids from the nose or mouth of an infected person. It is one of the most infectious agents known to man.

Most of the recent outbreaks in the US have started with an unvaccinated person from the US traveling to another country with measles outbreaks and bringing it back to the US. Measles is very contagious and the virus can live for up to two hours on surfaces infected patients have touched or in the air where they may have coughed or sneezed. As a result, anyone in an airport or crowded venue such as an amusement park has a chance of coming into contact with measles.

Is the measles vaccine safe?

Yes, very. A vaccine, like any medicine, is capable of causing side effects but usually these are mild, such as pain or swelling at the injection site and a fever that lasts a day or two. The risk of the measles vaccine causing serious harm is extremely small. Getting the measles vaccine is much safer than getting the measles infection.

What are the symptoms of the measles?

The most recognizable symptom of measles is a very high fever accompanied by a red or brownish blotchy rash, although this is not the only symptom.

Before the rash appears, children with measles develop cold-like symptoms, including:

Cough

Runny nose

Fever

Red, watery eyes

These symptoms tend to get worse during the first 1 to 3 days of the illness.

We have a trip to Disneyland planned. Should we cancel? What about other travel?

Health department officials in California have stated that if you and your children are fully vaccinated, you do not need to worry about going to Disneyland. Be sure your child's immunizations are up-to-date if traveling outside the US. Tell your pediatrician if you are traveling outside the country--including Europe. In most cases, children 6 months of age or older can get an additional, early dose of the measles, mumps and rubella (MMR) vaccine.

When do children need to get the measles vaccine?

The American Academy of Pediatrics (AAP), the Centers for Disease Control and Prevention, and the American Academy of Family Physicians all recommend children receive the MMR vaccine at age 12-15 months, and again at 4-6 years. Children can receive the second dose earlier as long as it is at least 28 days after the first dose.

High immunization rates in a community protects those who are too young to be vaccinated, including infants under 12 months of age. These infants are at the highest risk of serious illness, hospitalization, and death due to measles.

How long does the measles vaccine provide protection?

The measles vaccine is very effective in protecting against measles. However, no vaccine is 100% protective so very rarely, people who are vaccinated may develop measles. Some people may also be at risk for getting the measles if they only received 1 dose of the measles vaccine, which was the recommendation until 1989 when it changed to 2 doses. The second dose of measles vaccine increases protection to greater than 95%.

I'm not sure if I've received measles vaccine. Do I need a booster?

If you are not sure if you or your children have been fully vaccinated against measles, talk to your doctor to see if anyone in your family needs to be vaccinated. There is no risk to receiving measles vaccine if you have been immunized before. Measles is a live vaccine so children with immune problems or receiving medications that suppress the immune system should not receive the measles vaccine. Your pediatrician is your best source of advice on vaccinations.

The information contained on this Web site should not be used as a substitute for the medical care and advice of your pediatrician. There may be variations in treatment that your pediatrician may recommend based on individual facts and circumstances.